docs: Add Claude Code writing style guide

Add .claude/rules/writing-style.md with documentation writing guidelines
for AI assistants. Based on Apify style guide and TC-MO's technical
writer feedback from PR #2185.

Includes:
- Core principles (simple, factual, technical)
- Formatting rules (headings, bold, lists)
- Grammar guidelines (articles, Oxford comma)
- Terminology standards (Actor capitalization, word choice)
- Common mistakes to avoid

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mnmkng

.claude/rules/writing-style.md

@@ -0,0 +1,207 @@
+# Apify Documentation Writing Style
+
+Instructions for AI assistants writing Apify documentation. Based on Apify style guide and technical writer feedback.
+
+## Core Principles
+
+1. **Simple** - Get to the point. No sentence over 30 words. Every sentence delivers information.
+1. **Factual** - Back up claims with evidence. Use numbers, not vague qualifiers.
+1. **Technical** - Write for developers. Don't oversimplify. Link to fill knowledge gaps.
+
+> Write the same way you would explain something to a person sitting next to you.
+
+## Language & Tone
+
+### US English
+
+Use "analyze" not "analyse", "color" not "colour".
+
+### Imperative tone
+
+Use direct instructions, not soft recommendations:
+
+| Avoid | Prefer |
+|-------|--------|
+| We recommend pinning the version | Pin the version |
+| You should use the latest SDK | Use the latest SDK |
+| It's best to avoid hardcoding | Avoid hardcoding |
+
+### No sales language
+
+| Avoid | Prefer |
+|-------|--------|
+| Experience Apify, the ultimate platform! | Welcome to Apify, the cloud web scraping platform. |
+| Our highly efficient system | Apify's system handles 500K requests per minute |
+
+### Avoid first person
+
+Use "you" to focus on the reader. Avoid "I", "me", "myself" in docs.
+
+| Avoid | Prefer |
+|-------|--------|
+| I recommend using version 22 | Use version 22 |
+| In my experience, this works better | This approach is more reliable |
+
+## Formatting
+
+### Headings
+
+**Sentence case only.** No title case.
+
+| Avoid | Prefer |
+|-------|--------|
+| Store And Manage Data | Store and manage data |
+
+**No gerunds (-ing forms).** Use noun phrases or imperatives.
+
+| Avoid | Prefer |
+|-------|--------|
+| Finding available tags | Available tags |
+| Getting started with Actors | Get started with Actors |
+| Understanding the API | API overview |
+
+Rationale: Noun-phrase headings are more scannable and search-friendly (Microsoft style guide).
+
+### Bold
+
+Use bold sparingly. Don't bold:
+- List introductions
+- Code block introductions
+- Section labels when context is clear
+
+| Avoid | Prefer |
+|-------|--------|
+| **Examples:** | Examples: |
+| **In your Dockerfile**, use... | In your `Dockerfile`, use... |
+
+Bold is for critical warnings or key terms, not routine structure.
+
+### Ordered lists
+
+Use `1.` for all items (not sequential numbers). Easier to maintain:
+
+```markdown
+1. First step
+1. Second step
+1. Third step
+```
+
+### Parallel structure
+
+All items in a list must follow the same grammatical pattern:
+
+```markdown
+# Avoid - mixed patterns
+1. Reproducibility - your builds behave the same
+1. Predictability - you know which version
+1. Easier to track down issues
+
+# Prefer - consistent pattern
+1. Reproducibility - Your builds behave the same way
+1. Predictability - You know exactly which version you're running
+1. Debugging - Version-specific issues are easier to track down
+```
+
+### Em dashes
+
+**Don't use em dashes (—).** LLMs overuse them. Use hyphen with spaces ( - ) instead.
+
+## Grammar
+
+### Articles in definitions
+
+Include "a/an" before nouns in definition lists:
+
+| Avoid | Prefer |
+|-------|--------|
+| `{version}` - Node.js version only | `{version}` - A Node.js version only |
+
+### Oxford comma
+
+Always use the serial comma:
+
+| Avoid | Prefer |
+|-------|--------|
+| pencil, eraser and notebook | pencil, eraser, and notebook |
+
+### "the" before products
+
+Use "the" before "Apify platform", "Apify SDK", etc.
+
+| Avoid | Prefer |
+|-------|--------|
+| I use Apify platform | I use the Apify platform |
+
+## Terminology
+
+### Capitalization
+
+- **Actor** - Always uppercase when referring to Apify Actors
+- **Apify Proxy**, **Apify Console**, **Apify Store** - Product names, capitalized
+- **the Apify platform** - Lowercase "platform", include "the"
+- **task**, **schedule** - Lowercase
+
+### Word choice
+
+| Word | When to use |
+|------|-------------|
+| legacy | Feature is deprecated or will be removed |
+| alternative | Valid approach, but not the preferred one |
+| deprecated | Feature will be removed in a future version |
+
+## Links
+
+### Action-oriented text
+
+| Avoid | Prefer |
+|-------|--------|
+| [actor-node-playwright tags](url) | [View actor-node-playwright tags](url) |
+| See the [documentation](url) | [Read the documentation](url) |
+
+### Trim filler words
+
+| Avoid | Prefer |
+|-------|--------|
+| visit the Docker Hub tags page | visit Docker Hub |
+| check out the official docs | see the documentation |
+
+### Actor references
+
+First mention: Actor name with link, capitalized.
+
+```markdown
+[Website Content Crawler](https://apify.com/apify/website-content-crawler)
+can crawl websites and extract text content.
+```
+
+## Code Examples
+
+- Use backticks for file names, commands, config keys
+- Prefer complete, runnable examples
+- Add comments only when code isn't self-explanatory
+- Match versions in examples (e.g., Dockerfile tag matches package.json version)
+
+## Numbers & Formatting
+
+- Thousands: comma separator ($1,000)
+- Decimals: period ($9.8)
+- Money: symbol before amount ($49, not 49$)
+- Dates: August 5, 2024 (never 5.8.2024)
+- Time: 5 pm or 5 PM (space after number)
+
+## Common Mistakes
+
+Patterns to avoid:
+- "Happy scraping!" closings
+- Em dashes
+- Title case headings
+- Gerunds in headings
+- Bold for routine structure
+- "Ok" (use "OK" or "okay")
+- Missing "the" before "Apify platform"
+- Sales language ("ultimate", "cutting-edge", "supercharge")
+- Vague claims without numbers
+
+## Reference
+
+Full Apify style guide: https://www.notion.so/apify/de9fbb99dcd84665b6d3f790fc88b3b6